The document discusses different types of solar thermal power generation systems that use mirrors to collect sunlight and produce steam to drive turbines for power generation. It describes the main types as parabolic trough systems, solar power tower systems, solar dish/engine systems, and compact linear Fresnel reflectors. These systems work by using mirrors to concentrate sunlight and heat a working fluid like molten salt that is then used to generate electricity via steam turbines. The document also discusses advantages like no fuel costs, disadvantages like high installation costs, and challenges around energy storage and bringing costs down further.

2. Introduction
• Solar thermal power generation systems use mirrors to collect
sunlight and produce steam by solar heat to drive turbines for
generating power.
• This system generates power by rotating turbines like thermal and
nuclear power plants, and therefore, is suitable for large-scale power
generation.

3. Solar Power Generations
There are two main ways of generating energy from the sun:
Photovoltaic (PV) Concentrating Solar Thermal (CST)
Converts sunlight directly Generate electricity indirectly
into electricity.

4. History
• In 1866, Auguste Mouchout used a parabolic trough to produce steam for the
first solar steam engine.
• In 1886, The first patent for a solar collector was obtained by the Italian
Alessandro Battaglia in Genoa, Italy.
• In 1913, Frank Shuman finished a 55 HP parabolic solar thermal energy station in
Maadi, Egypt for irrigation.
• In 1929, The first solar-power system using a mirror dish was built by American
Scientist Dr. R.H. Goddard.
• In 1968, The first concentrated-solar plant, which entered into operation in
Sant'Ilario, near Genoa, Italy.
• in 1981, The 10 MW Solar One power tower was developed in Southern
California.
• In 1984, The parabolic-trough technology of the Solar Energy Generating Systems
(SEGS) begun its combined capacity is 354 MW.
• In 2014, The world's largest solar thermal plant (392 MW) achieves commercial
operation in Ivanpah, California, USA.

5. Solar Thermal Systems
There are two types of solar thermal systems:
Passive: A passive system requires no equipment, like when heat
builds up inside your car when it's left parked in the sun.
e.g. Thermal chimneys
Active : An active system requires some way to absorb and collect solar
radiation and then store it.
e.g. Solar thermal power plants

6. Basic Working Principle
• Mirrors reflect and concentrate sunlight.
• Receivers collect that solar energy and convert it into heat energy.
• A generator can then be used to produce electricity from this heat
energy.

7. Thermal energy storage (TES)
TES are high-pressure liquid storage tanks used along with a solar thermal
system to allow plants to bank several hours of potential electricity.
• Two-tank direct system: solar thermal energy is stored right in the same
heat-transfer fluid that collected it.
• Two-tank indirect system: functions basically the same as the direct
system except it works with different types of heat-transfer fluids.
• Single-tank thermocline system: stores thermal energy as a solid, usually
silica sand.

8. Types of solar thermal power plants
Parabolic trough system Solar power tower systems Solar dish/engine system
Compact linear Fresnel reflector

9. Parabolic trough System
• A parabolic trough consists of a linear parabolic reflector that concentrates
light onto a receiver positioned along the reflector's focal line.
• The receiver is a tube positioned directly above the middle of the parabolic
mirror and filled with a working fluid.
• The reflector follows the sun during the daylight hours by tracking along a
single axis.
• A working fluid (e.g. molten salt) is heated to 150–350 °C (423–623 K (302–
662 °F)) as it flows through the receiver and is then used as a heat source
for a power generation system.

11. Parabolic trough System (Image)

12. Solar power tower systems
• Power towers (also known as 'central tower' power plants or 'heliostat'
power plants).
• These designs capture and focus the sun's thermal energy with thousands
of tracking mirrors (called heliostats) in roughly a two square mile field.
• A tower resides in the center of the heliostat field. The heliostats focus
concentrated sunlight on a receiver which sits on top of the tower.
• Within the receiver the concentrated sunlight heats molten salt to over
1,000 °F (538 °C).
• The heated molten salt then flows into a thermal storage tank where it is
stored, maintaining 98% thermal efficiency, and eventually pumped to a
steam generator.
• The steam drives a standard turbine to generate electricity.

14. Solar power tower systems (Image)

15. Solar dish/engine system
The system consists of a stand-alone parabolic reflector that concentrates
light onto a receiver positioned at the reflector's focal point.
The working fluid in the receiver is heated to 250–700 °C (523–973 K
(482–1,292 °F)) and then used by a Stirling engine to generate power.
Parabolic-dish systems have the highest efficiency of all solar technologies
provide solar-to-electric efficiency between 31–32%.
Stirling Engine 

17. Solar dish/engine system (Image)

18. Compact linear Fresnel reflector
• Linear Fresnel reflectors use long, thin segments of mirrors to focus
sunlight onto a fixed absorber located at a common focal point of the
reflectors.
• These mirrors are capable of concentrating the sun’s energy to
approximately 30 times its normal intensity.
• This concentrated energy is transferred through the absorber into some
thermal fluid.
• The fluid then goes through a heat exchanger to power a steam generator.

20. Compact linear Fresnel reflector (Image)

21. Enclosed parabolic trough
• The enclosed parabolic trough solar thermal system encapsulates the components within a
greenhouse-like glasshouse.
• The glasshouse protects the components from the elements that can negatively impact system
reliability and efficiency.
• Lightweight curved solar-reflecting mirrors are suspended from the ceiling of the glasshouse by
wires.
• A single-axis tracking system positions the mirrors to retrieve the optimal amount of sunlight.
• The mirrors concentrate the sunlight and focus it on a network of stationary steel pipes, also
suspended from the glasshouse structure.
• Water is pumped through the pipes and boiled to generate steam when intense sun radiation is
applied. y steel pipes, also suspended from the glasshouse structure.

22. Enclosed parabolic trough (Image)

23. Advantages of Solar Thermal Energy
• No Fuel Cost
• Predictable, 24/7 Power
• No Pollution and Global Warming Effects
• Using Existing Industrial Base

24. Disadvantages of Solar Thermal Energy
• High Cost
• Future Technology has a high probability of making CSP Obsolete
• Ecological and Cultural Issues
• Limited Locations and Size Limitations
• Long Gestation Time Leading to Cost Overruns

25. Major Challenges
• The major challenge are the Installation Cost and energy storage.
• The costs are still far higher than fossil fuel plants based on units of
energy produced.
• The hot water storage products are often stretched to their limits.
• Alternatives could be phase change materials (PCMs) or thermo-
chemical materials (TCMs).
• In addition to sensible heat, the technologies of latent heat and
thermo-chemical energy storage are on their way to becoming very
promising solutions for the future of solar heating and cooling.

26. Further Development-Thermal chimneys
• Thermal chimneys are passive solar ventilation systems, which means they are
non-mechanical.
• Typically made of a black, hollow thermal mass with an opening at the top for
hot air to exhaust.
• Inlet openings are smaller than exhaust outlets and are placed at low to medium
height in a room.
• When hot air rises, it escapes through the exterior exhaust outlet, either to the
outside or into an open stairwell or atria.
• Turbines similar to those used in hydroelectric power plants convert the air flow
into mechanical energy.

27. Thermal chimney

28. Conclusion
• In the face of global warming, rising fuel costs and an ever-growing
demand for energy, energy needs are expected to increase by nearly
the equivalent of 335 million barrels of oil per day, mostly for
electricity.
• By concentrating solar energy with reflective materials and
converting it into electricity, modern solar thermal power plants, if
adopted today as an indispensable part of energy generation, may be
capable of sourcing electricity to more than 100 million people in the
next 20 years. All from one big renewable resource: THE SUN.

29. THANK YOU

30. References
• http://science.howstuffworks.com/environmental/green-tech/energy-production/solar-thermal-
power4.htm
• http://www.flowserve.com/Industries/Power-Generation/Concentrated-Solar-Power
• http://en.wikipedia.org/wiki/Solar_thermal_energy
• http://www.greenworldinvestor.com/2011/07/07/advantages-and-disadvantages-of-solar-
thermal-energy-power-towersparabolic-troughs/